Hot-water air heating unit



p 1951 E. w. CALDWELL 2,567,801

HOT WATER AIR HEATING UNIT Filed April 25, 1950 3 Sheets-Sheet l [00:11:W CALDWELL,

INVENTOR ATTORNEYS.

Sept. 11, 1951 E. w. CALDWELL 2,567,301

HOT WATER AIR HEATING UNIT Filed April 25, 1950 5 Sheets-Sheet 2 JATTORNEYS.

P 11, 1951 E. w. CALDWELL I 2,567,801

' HOT WATER AIR HEATING UNIT 3 Sheets-Sheet I5 Filed April 25, 1950fUGEA/E W (ALDWELL,

INVENTOR.

BY afrw+ ATTORNEYS.

Patented Sept. 11, 1951 UNITED STATES PATENT OFFICE 2,567,801 HOTWATERAIIit HEATING UNIT Eugene W. Caldwell, Maiden, N. 0. ApplicationApril 25, 1950, Serial No. 158,032

1 Claim. 1

This invention relates to heating units and more especially to animproved radiator type forced air heater.

The primary object of this invention is to provide an improvement in ahot water heater of a type having a radiator provided with pipes ortubes back of which a fan is disposed for circulating air through theradiator and having means for admitting water or the like to the pipesin the radiator under pressure, the improvement comprising an electricalheating element disposed within a container into which the water in thepipes is also admitted for heating the water in the pipes and animproved thermostatic regulator for said heating element.

There have, heretofore, been many heaters of substantially the typeheretofore described which were provided with an electrically operablefan for circulating air past the pipes in the radiator and this fanbeing controlled by a suitable thermostat or the like. However, due tochanges in temperature and atmospheric conditions, it sometimes happensthat the fan will remain inoperative for a considerable length of timewith the result that the pipes in the radiator will become overheatedand the water or other fluid therein will evaporate thus causing theradiator pipes to give on an undesirable amount of heat and also causingthe element to become overheated and to burn out and, of course, causinga relatively large consumption of electrical current resulting in costlyoperation of the heating unit.

It is, therefore, another object of this invention to provide a heaterof the type described with an improved control means including a closedtube which projects into the container into which the water or otherfluid in the pipes is also admitted and which is adapted to be submergedin the fluid, this tube having a rotatable shaft mounted therein andextending longitudinally thereof and being surrounded by a coiledspring, the other end of the closed tube relative to the container beingslidably and rotatably penetrated by the shaft disposed within the tubeand this shaft having suitable circuit breaking means on the outer end,such as one or more mercury switches, through which current passes froma source of electrical energy to the heating element disposed within thecontainer.

The shaft within the closed tube is surrounded by a torsion spring, oneend thereof being connected to the shaft and the other end beingsuitably secured in'fixed relation to the tube. The torsion spring isresponsive to changes in .temperature so that upon the heating elementin the container having heated the water to a desired temperature,regardless of whether or not the fan is operating, the torsion springwill transmit partial rotation to the shaft which it surrounds toactuate the circuit breaking meansto open the circuit to the heatingelement when the water or other fluid in the radiator pipes has reacheda predetermined temperature, preferably, just below boiling point.

It is evident that, upon the temperature of the water or other fluid inthe container being lowered to a predetermined temperature by the fan orthrough dissipation of the heat in the radiator pipes by any othermeans, the torsion spring will contract in such a manner as to againclose the circuit to the heating element from the source of electricalenergy.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds when taken in connection withthe accompanying drawings in which- Figure 1 is a side elevation of theimproved. heating unit omitting the Wall of the casing nearest theobserver for purposes of clarity and showing many of the parts incross-section;

Figure 2 is an enlarged elevation with parts in section, lookingsubstantially along the line 22 in Figure 1, and showing a part of theimproved control apparatus for the electrical heating elements;

Figure 3 is an elevation with parts in section looking substantiallyalong the line 3-3 in Figure 1;

Figure 4 is a sectional plan View through the water heating container ormanifold taken along the line 4-4 in Figure 3;

Figure 5 is an enlarged fragmentary sectional plan view takensubstantially along the. line 55 in Figure l and showing the apparatusresponsive to the temperature of the water in the heater for controllingthe flow of current to the electrical heating elements for heating thewater;

Figure 6 is a diagrammatic view showing the various electrical parts ofthe apparatus schematically.

Referring more specifically to the drawings, there is shown a heatingunit of a type such as is adapted to be suspended from the, ceiling of abuilding, from a wall of the building or mounted on the floor. However,it is to be understood that the present invention may be used inassociation with many types of hot water radiator space heaters, theheating unit appearing in the drawings being shown by way ofillustration only.

Referring to Figures 1 and 3, the numeral [0 broadly designates aradiator including a plurality of spaced vertically disposed tubes orradiator pipes I I which penetrate a plurality of horizontally disposedand vertically spaced vanes I2 which are fixed to the radiator pipes IIin the usual manner such as by soldering. The upper ends of the pipes IIare suitably connected to and communicate with an upper manifold orcontainer I5 which has an internally threaded adapter I6 securedthereto, as by welding at H, and communicating therewith.

A nipple 28 has one end thereof threadably embedded in the adapter I6and the other end thereof is connected to an elbow H to which the upperend of a vertically extending pipe nipple 22 is threadably connected toa pipe elbow 23 to the other end of which a pipe 24 is threadablyconnected, this pipe 24 extending from a suitable source of fluid underpressure, such as water, for admitting water under pressure to themanifold- I5 and the radiator pipes II as well as a lower manifoldorcontainer 30. The elbows 2I and 23 and the pipe nipple 22 form a trapso the heat of the water in the radiator III will not be transmitted tothe pipe 24, since the heat of the water under pressure will not traveldownwardly from the upper pipe 20. The manner in which the water isdirected to the upper manifold I5 is a part of the present invention.The water is omitted from the drawings for purposes of clarity.

The lower endsrof the vertically disposed radiator pipes II are suitablyconnected to and communicate with the lower manifold 35. Both of themanifolds I5 and 35 are box-like in con struction, being closed at allsides and at the upper and lower ends thereof. The lower manifold 30includes left-hand and right-hand end walls 5i and 32, respectively(Figures 3 and 4), which are suitably connected to front and rear walls33 and 34, respectively, the end walls 3! and 32 and the front and rearwalls 33 and 35 being suitably connected to upper and lower walls 35 and35, respectively.

A suitable pipe adapter 38 is secured, as by welding at 39, to the rearwall 35 and communicates with the lower manifold 35. This adapter 38 isadapted to threadably receive a pipe nipple I3 whose other end isthreadably connected to a manually operable valve 4 This valve 55 has adischarge pipe 55 connected to its side remote from the side to whichthe nipple 53 is connected and the pipe 5 may be connected to a seweragepipe line if so desired. The valve 44 may be opened for changing thesupply of water in the radiator I and in initially admitting water tothe radiator II]. The pipes 24 and 55 may support the heating 'unit ifso desired or there may be suitable brackets, not shown, for mountingthe heating unit. The manner of heating the water in the lower manifold30 and the control means therefor will' be later described in detail.

A suitable housing broadly designated at 55 is suitably secured at itslower end to opposed end walls BI and 32 of the lower manifold 30, as ati (Figure l), and its upper wall is'also supported on the upper manifoldI5, the upper manifold I5 having suitable nuts 52, only one of which isshown, secured thereto, as by welding, in which screws 53 are threadablyembedded and which screws also penetrate the upper wall of the housing50 for securing the same to the upper manifold I5.

The housing 50 has an opening 55 provided with suitable swingablelouvres 56 which may be 4 adjusted in a conventional manner or which maybe loosely pivoted to be swung open by a blast of air from a fan to bepresently described. The rear of the housing I5 is closed by a rear wallor panel 58 secured to the walls of the casing 50 as by bolts 59. Therear wall or panel 58 of the casing 55 has a suitable opening 6| thereinthrough which the pipe nipple 25 extends. The rear panel 58 is alsoprovided with a substantially centrally disposed circular opening 52which is provided to permit a blast of air caused by a fan 63 to passthrough the opening 52 and past the pipes II of the radiator It! to thustransfer the heat from the tubes II through the opening 55 and betweenthe louvres 55 and to discharge the same into the atmosphere.

The fan 63 is surrounded by a plurality of horizontally spaced guardrings 54 which vary in size and which are secured to a plurality ofdiagonally extending brace wires 56 of which only four are shown inFigure 3. These brace wires 55 are secured at their free ends as byscrews 61, to the rear surface of the rear panel 58 and extendrearwardly and are suitably secured at their rearmost'ends to anelectric motor III. The electric motor III has a shaft II extendingforwardly therefrom and on which the fan 63 is fixedly mounted. Themotor It also has electric wires I2 and I3 extending therefrom to asuitable source of electric energy in a manner to be presentlydescribed.

Referring to Figures 6, it will be observed that the wire I2 isconnected at its end remote from the motor II! to a lead wire 14 and thewire I3 is connected at its end remote from the electric motor 10 to asuitable manually adjustable electrically operable thermostat controlapparatus TI to the other side of which a wire I8 is connected. The endof the wire it remote from the thermostat TI is connected to a lead wire8I and, upon the circuit being completed by the manually adjustablethermostat, in a manner well known to those familiar with the art, thecurrent will flow from the lead wire 8! through the wire I8, thermostatI'I, wire I3, motor I0, wire I2 and lead wire I I- to complete thecircuit to the electric motor Ill and to cause rotation of the shaft IIand the. fan 63. The heating unit as heretofore described isconventional and it is with this heating unit or a similar apparatusthat the present invention is adapted to be associated.

Now, referring to Figures 3, 4 and 6, there will be observed a pair ofspaced heating coils and 85 which are of tubular construction and whichhave electrical heating elements or resistors 8! and 55, respectively,therein. The right-hand end wall 32 of the lower manifold 35, in Figure4, has an opening, defined by the dotted lines SI and 82, therein whichis large enough to permit ingress and egress of the electrical heatingcoils 85 and 85 for installation purposes. This opening is covered by areinforcing plate I93 suitably secured to the right-hand end wall 32 of.the lower manifold 35 as by screws 54. The

reinforcing plate 53 is slidably penetrated by a restricted portion of aheating coil support member, S B suitably secured to the outer surface,of the reinforcing. plate 93 as by screws 91.

The heating coils 85and 86 penetrate the heating coil support member 95and the exposed ends thereof are bridged by suitable bus bars I05 andiIIlI. These bus bars I55 and NH are suitably connected, as bysoldering, to the electrical heating elements 81 and 88 in the coils 85and 86, re-

spectively. Respective wires I02 and I83 are COD-9 nected to the busbars'I00 and ml at one of their ends, their other ends being connectedto respective closed tubular elements I04 and I05 of a mercury switchdesignated broadly at I06.

Theclosed tubular elements I04 and I05 contain an electricallyconductable fluid such as balls of mercury I01 and I08, respectively,which, when the tubular elements I04 and I05 are in the tilted position,shown in Figures 3 and 6, will com plete a circuit between the wires I02and I03 and respective wires I II and H2 which are also suitablyconnected to the closed tubular elements I04 and I05. Th ends of thewires III and H2 remote from the closed tubular elements I04 and I05 areconnected to a lead wire I I4 and the lead wire BI, respectively A wireH5 is connected intermediate the ends of the wire II I and is connectedat its other end to the lead wire I4.

The mercury switch I06 includes a plate member I20 having a hub portionI2I (Figure 5) integral therewith which-is slidably penetrated. by anenlarged portion I22 of 'a shaft I23 and is secured on this enlargedportion I22 by a set screw I24. The plate I20 has suitable spring clipsI28 projecting outwardly therefrom within which the closed tubularelements I04. and I05 are clampingly secured.

The shaft I22 is oscillatably mounted in a hub portion I2I of anadjustable control member I30 which has an upwardly projecting portionI3I (Figure 2) integral therewith provided with an arcuate slot I32therein which is penetrated by an adjustment screw I33 for securing thecontrol member I30 in adjusted position on a vertically disposed plateI34. The vertically disposed plate I34 has suitable graduations I35 01'other indicia thereon to determine the proper position for the controlmember I 30, this control member I 30 being adapted to control the heatof the water or other fluid in the lower manifold 30 in a manner to blater described. The plate I34 is mounted in adjusted position between apair of lock nuts I35 and I3? threadably mounted on an enlarged portionI 40 of a tubular member I 4| which extends into the lower manifold 30and is closed at its inner end as at I42. This inner portion of thetubular member I4I is'adapted to be submerged in the water in the lowermanifold 30, however, the water does not enter the tubular member I 4|.

Th rear wall 34 of the lower manifold 30 has a second pipe adapter I43suitably secured thereto, as by welding at I44 (Figure 5), and the rearend of this adapter I43 is threaded for reception of a second adapter orpipe reducer I45 which threadably receives the enlarged portion I40 ofthe tubular member I 4|. It is thus seen that the plate member I34 issupported by the tubular member I4I which is, in turn, supported by therear wall 34 of the lower manifold .30.

The hub portion I2'I of the control member I30 is slidably fitted in thetubular member MI and has a restricted portion I41 integral therewithwhich is surrounded by one end of a torsion spring I50, this torsionspring I 50 being connected at one end to the restricted portion I4! ofthe hub IT! by any suitable means such as a screw I5I. In order that thetorsion spring I50 may be properly sensitive to changes in temperature,it is preferable that this torsion spring I50 be of a flat wire materialand of considerable length relative to its diameter. The other orright-hand end of the torsion spring I 50, in Figure 5, is suitablysecured to the right-hand end of the shaft I23, this shaft I23 beingslotted as 6 at I 53 for reception of the right-hand end of the torsionspring I50. The walls of the slot I53 are held in engagement with theright-hand end portion of the torsion sprin I50 by any suitable meanssuch as a cotter pin I54.

In operation, the manually adjustable thermostat TI is adjusted to thedesired room temperature and when the room is below the desiredtemperature the current will flow to the electric motor I0 in the mannerheretofore described to cause rotation of the fan 63 and to cause air tocirculate between the vanes I2 and past the radiator pipes II to bedischarged through the opening 55 between the louvres :55 into thesurrounding atmosphere for discharging heat from the pipes The controlmember I 30 is also adjusted to the desired temperature for the water orother fluid within the radiator I0, it being evident that it will not benecessary to heat the Water to as high a temperature during relativelywarm atmosperic conditions as it will during relatively cold atmosphericconditions. The control mechanism for controlling the heat of the waterin the radiator I0 may be adjusted by loosening the screw I33 androtating the control member I30 to the desired temperature as indicatedon the plate I34. This will, of course, increase or decrease theexisting torsion in the torsion spring I50.

Assuming the water or other fluid in the lower manifold 30 to be belowthe desired temperature, the closed tubular elements I04 and I05 ofthe.- mercury switch I06 will be disposed in substan-- tially theposition shown in Figures 3 and 6 and this will permit current to flowto the heat-- ing elements 81 and 88 in the water heating coils 85 and86. A circuit will be completed tothe heating elements 87 and 88- from.the lead wires H4 and H5, through the wire II I, the mercury ball I01,wire I02, through the bus bar I00, to one end of both of the heatingelements 81 and 83 and thenthrough the bus bar IOI, wire I03, mercuryball I08 in the closed tubular element, I05 and wire M2 to the lead wireBI thus completing the circuit to the electrical heating elements 81 and88.

It is not essential that there be two closed tubular elements, such asthe elements I04 and I05, as it is evident that a single switch meanswill operate satisfactorily in completing a circuit to the electricalheating elements 87 and 88 it merely being necessary to change thearrangement of the wiring in a manner well known to anyone skilled inthe art.

The heating coils 85 and 86, having the heating elements 81 and 88therein, will then heat the water in the lower manifold 30 as well asthe pipes II' and the nipple 20. Inasmuch as the water or other fluid isdirected to the radiator I0, including the upper manifold I5, throughthe pipe 24 under pressure, as heretofore stated, by offsetting the pipe24 relative to the nipple 20, and the pipe 24 being positioned at alower elevation than the pipe 20, the water or other fluid in pipe 24will not travel downwardly through an off-set pipe to the pipe 24.

Now, when the temperature of the water in the lower manifold 30 hasreached a predetermined temperature, according to the position of theadjustable control member I30, the torsion spring 50 will expand due tothis change in temperature and will thus partially rotate the shaft I22in a clockwise direction in Figure 3 and, in so doing, will cause themercury switch I06 to rotate in alike manner to where the closed tubularelements I04 and I will be disposed in a substantially level position orwill extend at an angle opposite from the angle at which they are shownin Figures 3 and 6. This will result in the mercury balls I01 and I08 inthe closed tubular elements I04 and I05 moving out of engagement withthe corresponding wires I02 and III and I03 and H2 thus opening thecircuit from the lead Wires 8I, I I4 and M5 to the electrical heatingelements 81 and 88 in the heating coils B5 and 86 until the temperatureof the water in the lower manifold 30 will have lowered sufiiciently towhere the spring I50 will again contract and will transmit partialcounterclockwise rotation to the shaft I22 to again tilt the closedtubular elements I04 and I05 to substantially the position shown inFigures 1, 3, and 6.

It isthus seen I have provided an improved control means forautomatically controlling the flow of current to electrically operableheating elements in accordance with the temperature of the liquid whichthe heating elements are adapted to heat and wherein the controlapparatus is adjustable according to the desired temperature of thewater or other liquid in the lower manifold 30 of the heating unit. Theswitch I06 is adjustable on the end of the shaft I22 to produce adesired sensitivity in reaction of the control apparatus in affectingthe flow of current to the electrical heating elements 8! and 88.Although it is not necessary, the torsion spring I50 may be made of abi-metallic material if so desired to thereby increase its sensitivityto changes in temperature.

In the drawings and specification there has been set forth a preferredembodiment of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaim.

I claim:

An improved temperature regulator in a space heater, said space heaterhaving upper and lower water containing manifolds, means connecting saidmanifolds, said space heater also being provided with means forintroducing water under pressure into said manifolds and said spaceheater also having a frame,- said improvement comprising at least oneheating coil positioned within said lower manifold and having the freeend thereof insulatably mounted in one of the walls of said lowermanifold, a bracket secured to said frame adjacent saidlower manifold, aclosed tubular member fixedly mounted in said bracket and extendingwithin said lower manifold, a gauge member adjustably mounted in the endof said tubular member extending from said lower manifold, a shaftrotatably mounted in said gauge member and extending within said tubularmember, a coiled thermostatic element positioned within said tubularmember and about said shaft and having one of its ends connected to saidshaft and the other of its ends connected to said gauge member, a switchbracket secured to the outer end of said shaft, at least one clipsecured to said switch bracket, a mercury tube positioned in said clip,a source of electrical energy. an electrical circuit connecting saidmercury tube with said source of electricity and with said free end ofsaid heating coil, said circuit being broken at said mercury tube, saidmercury tube having mercury therein adapted to close said circuit uponsaid tube being moved to switch closed position, whereby heat in saidlower manifold will cause said shaft to rotate a predetermined amount tomove said mercury tube to switch open position and upon said lowermanifold cooling, said shaft will rotate in the opposite direction tomove said mercury tube to switch closed position to actuate said heatingcoil to heat the water in said lower manifold.

v EUGENE W. CALDWELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,920,284 Wells Aug. 1, 19331,925,760 Huth Sept. 5, 1933 1,932,071 Hodges Oct. 24, 1933 2,197,298Cobb Apr. 16, 1940 2,244,172 Novak June 3, 1941 2,360,071 Noll Oct. 10,1944

